<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        a{
            width: 120px;
            text-align: center;
            text-decoration: none;
            color:inherit;
            font-size: 20px
        }
        nav>a{
            position: relative;
            display: inline-block;
            padding: .3em 1em 0;
        
            
        }
        nav{
            margin: 100px;
        }
        nav a::after{
            content: "";
            position: absolute;
            height: 200px;
            width: 200px;
            top: -143px;right:0;left: -20px;bottom: 0;
            z-index: -1;     
            background: #ccc;     
            background-image: linear-gradient(hsla(0,0%,100%,.6), hsla(0,0%,100%,0));
            border: 1px solid rgba(0,0,0,.4);     
            border-bottom: none;
            border-radius: .5em .5em 0 0;
            box-shadow: 0 .15em white inset; 
            transform: perspective(.5em) rotateX(5deg);     
            transform-origin: bottom; 

        }
    </style>
</head>
<body>
    <nav>
        <a href="">home</a>
        <a href="">projects</a>
        <a href="">about</a>
    </nav>
</body>
</html>